620 A/C compressor mount

[Datfish]

https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=york+to+sanden+bracket+datsun&_sacat=0#

I hope to use the old bracket that was on my block and something from here...

[Gery]

Color me embarrassed.  The 620 I picked up already had some of the a/c components (York compressor, huge cast iron bracket, some ones...but not a completer set up.  I got the compressor out and am still struggling with the bracket.  It seems to be a poor design in that it blocks the plug on cylinder 4 and mashes the cable.  To do routine maintenance, one would need to remove the compressor and bracket.  In any case, I did not/do not  want an oem set up, but rather, a modern low draw compressor.  

Onwards and upwards"....

(ironically, I am currently installing a/c in my Karmann Ghia.  )

[Seeker > 620 KC]

On ‎07‎/‎18‎/‎2018 at 10:58 PM, Datfish said:

https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=york+to+sanden+bracket+datsun&_sacat=0#

I hope to use the old bracket that was on my block and something from here...

 

There’s a guy I know with a blue 620 in LA who wanted AC and does not have a shop to work in, but he was very creative utilizing what he had to work with, for this idea we’d discussed together. And, he kept the orig R12 Freon, which is easier to keep in the system vs  R134. (More later on R12 ca R 134) He used the original Datsun York 3 bracket system. But he still used the orig Datsun front steel plate bracket that also replaces the timing chain inspection cover, and he needed the 3rd short top comp bracket as well. It is a very complicated and ugly installation for sure, and makes access to other engine systems very difficult, but “Hey!” he has working AC in a 620! And he beat me by miles getting it up and working.

 

He bought a generic Sanden rotary steel-plate compressor mount plate. Cut off part of the top of orig Datsun 12 lb bracket so the Sanden mount would kinda mount flat. Then he redrilled the Sanden mount, in order to bolt it to the 12 lb cast iron bracket. He still needed ALL the orig brackets. Unfotunately, it only has two bolts holding the Sanden bracket to the 12 lb bracket. And there was something hap-hazard about the belt adjustment. Can’t remember if he couldn’t use the orig idler pulley, or if the compressor was only held in with 2 bolts and swung out, the belt tightness/adjustment was just hinky. He said it used the rotation of the compressor pump to keep the belt tight???

 

i haven’t thought it through if I’d trust using the 12 lb bracket by itself to bolt a Sanden universal mount bracket to. The extra ft bracket gives the orig 12lb brkt one more mount point, as it has all different size bolt diameters  attaching it to the engine. When I was installing and servicing these units in the 70’s I remember many of these having broken off engine bolts that had to be drilled out a retapped, some had to have motors pulled out to repair. Mechanics servicing or installing AC would over tighten bolts snapping them off, use impact guns in a rush, or simply leave bolts loose. The vibration from the York pumps cycling on and off would break bolts over time on these little alum head engines. My orig idea was to fab a newer Sanden bracket to fit the pass side of the motor, but there is still the challenge of not blocking access to the #1 plug. But the bigger hurdle for me.... I just too old, don’t have the welding skills, and don”t know anyone I can afford to make a simpler bracket. It is surely an opportunity for someone who does ? ( More in future posts about other existing  aftermarket AC comp mounts on Driver side, with and without smog pump,) 

 

Somewhere I have a few pics I snapped of the blue 620 installation for a reference, but I don’t recall if this installation resolved the non-access prob to the #1 spark plug or not, listed in Gery's  post above. 

 

Unfortunately, in his haste,  he also used the orig worn out clutch waterpump with a 7 blade fan, and the orig receiver-drier, and had not reinstalled his fan shroud. He drove it to Eagle Rock Swap Meet and had serious overheating issues and the AC system was just cool, not cold. I had a spare 8 blade orig fan (with shorter blades and more pitch) I sold him. He bought a new clutch water pump, installed it all with his fan shroud, and resolved the heating prob. But he needs to get a new receiver-drier to take any moisture out of the system to make it blow colder. But to do so he’ll have to capture all the R12 Freon out of the system, R&R the receiver drier, fav the system, and recharge it with Freon. Tip: Never re-use a condenser drier that has been exposed to the air for more than a day

 

I give this guy major kudos for putting together a working 620 AC AND a fairly bolt-on AC system, while living in an apt without having a garage to work in. His system gets him around LA, and to events and shows, But in the condition I last saw it, I would have serious concerns driving it long distance, like to the Fontana BBQ, or to the Williams AZ event . But with his kind of Ratsun ingenuity And determination I certainly have faith he’ll continue to get the dependability factor “dialed-in” over time. 

Edited July 20, 2018 by Seeker > 620 KC
Clarified a couple sentences

[Seeker > 620 KC]

 Datsun original In-dash evaporator AC unit and drive belt diagram sourced from a  1979 Datsun Factory Service Manual.  

Note: This diagram shows the entire evaporator, but not the plastic cover that hides the evaporator and prevents passengers from kicking it.

 

 

 

Edited July 20, 2018 by Seeker > 620 KC
Added 1979 620 FSM diagrams

[Seeker > 620 KC]

Datsun 620 engine bay orig AC diagram from the 79 Datsun/Nissan Factory Service manual

 

NOTICE:

 

This diagram depicts the real 8 blade AC fan for the large 5" bolt pattern clutch-water pump.

 

It eliminates the mechanical fuel pump and replaces it with a block-off plate. An electric fuel pump is required back by the gas tank.

 

It requires an extra drive pulley on the crank. It looks like the same pulley that is rubber mounted within a 720 harmonic balancer, but it would have to be cut,  pressed out, or heated up with a torch to remove it to match up. Wouldn't be able to do that in a junk yard!  

 

There are two different cooling housings for different year ranges. You'd have to go to the website carpartsmanual.com to look at the parts listings to see what the different parts went to which year ranges.

 

The front idler bracket/support compressor replaces the timing chain inspection cover.

 

Front cooling hoses need some re-routing.

 

 

 

 

Edited July 20, 2018 by Seeker > 620 KC
Added 79 620 FSM AC engine fitting diagram

[Seeker > 620 KC]

Diagrams compliments of carpartsmanual.com   

 

The AC diagrams are in various places. Be sure to open the different ones and look for other pages. Sub pictures often show model or year variations, or other related components like the electric fuel pump (F) below. It did not come stock on most 620's only the ones with AC, campers, or other unique situations. It appears there was an early and late variation in this diagram. One would have to check the parts listing on the website to confirm this.  

 

Please note this diagram indicates a standard 7 blade clutch-type fan.

This fan is the standard heavy duty clutch fan that came on the 620 L20b motors. Not sure about others it may have been on.

It is NOT the heavy duty AC fan that actually came in the AC kits. This fan will be depicted in the next post diagram.  If you go to Carpartsmanual.com and look at the individual parts listings below this diagram, you will see there are different part numbers for the different fans. There will also be a different pic of the 8 blade fan in one of the other diagrams.

 

This diagram also shows the in-dash ducting and the backside of evaporator cover that goes in the passenger leg area, but this diagram does not show the center vents. Unfortunately, you have to move between the different diagrams to find all the variations of the AC parts.

 

 

 

The factory AC fan had 8 shorter blades with more pitch vs. the standard 7 blade clutch fan with longer blades.

Through junkyard prowling I have learned  the 8 blade fan was also used on later model vehicles like the 1980 200SX with the EFI Z20 engine, and have matched them to my 620 AC fan.

 

More pitch = more pulled air vs. trying to achieve the same by using more torque on a longer flatter fan blade.

 

(But for all you minimalists who like to have manual fans and hidden wiring looms... at engine start-up, or with a hot motor sitting in freeway traffic... these fans do create lot of wind noise.)

 

SAFETY TIP: Do not install AC and attempt to use a 4 blade manual (no clutch)  fan with or without a fan shroud... you will overheat and seize your engine in short order!

 

You may be able to get by with a 7 blade clutch fan and a shroud, but be sure to check the longer fan clearance with your shroud.There seem to be a number of different fan shrouds available from different vehicles.

 

SAFETY TIP: If you are brave enough to install a new or used AC system on a used Datsun 620 engine with an old or original head gasket... Don't risk the life of your motor! You must ensure all components of the cooling system are in  Excellent condition:

 

Clutch fan is new or has great resistance when spun by hand (It should not spin a full revolution, if so replace it!)

Thermostat is opening at 180 degrees

Radiator is clean and not restricted

Rad cap seals and works

Cooling system has been flushed and runs clear

Cooling system holds pressure - no leaks or seepages

Freeze plugs look solid and are not crusty rusted or leaking (Don't forget the one on the back of the block between the engine block and trans!)

There is the correct percentage of anti-freeze/coolant in system

Heater control valve is not leaking

Hoses are not soft, bloated, and are in good shape

Oil change is fresh and regularly changed

Fan shroud is whole, complete, and not cracked. (I've seen half-shrouds on newbs cars! Duct tape it if cracked!)  

 

Last, but not least... Ensure your temp gauge is working and accurate!  Keep a religious eye on that gauge whenever using the AC, especially at low speeds or pulling a grade!    

If you maintain these, along with your AC system maintenance it will give you years of problem free cool to cold AC service. Remember this is 40 year old R12 evaporator technology. They did not perform like modern day evaporators.

If you ignore maintaining the cooling system, you will kill your 35-40 year old motor very quickly.

Stay cool!  

Edited July 20, 2018 by Seeker > 620 KC

[Seeker > 620 KC]

Now that the original Datsun factory AC system has been identified, it raises a lot of other questions/considerations for those wanting AC in their 620:

 

How technical are my mechanical skills? Do I know the types of AC seals and differences between R12 and R134? Do I how to successfully re-seal/convert AC hoses and compressors? Do I know the differences in refrigerant oils and not to mix them? Can I vacuum down an AC system? Do I have the equip for it or can borrow it?

 

Can I do this kind of upgrade in my driveway/garage with the tools I have?

 

Am I a bolt-on guy, or do I have the skills (or know someone/or a shop) who can fabricate custom compressor brackets and hoses etc.

 

Only you can answer these questions. If you still want to proceed, you'll also need to consider the following:

 

Do you have any access to R12 Freon? If so you can use an older R12 AC unit. If not you will have to completely flush the old system out and convert it to R134. Do you know about these before rushing out and buying a new or used AC unit? R12 is easier to re-seal and keep in the system, but it is also going for $30-35 per lb on Craigs list. Not sure what a shop charges, most no longer stock it due to cost and certification. The typical 620 AC system uses 3 to 3 1/2 lbs =   $105 to 125 for Freon, before leak checking!  R134 is harder to keep in a used system. The entire AC system including evaporator will have to be first flushed,  then resealed with R134 seals. The compressor will have to have ALL oil drained, as R12 oil and R134 oil is not compatible. Then it will need to be resealed.

 

Do I simply want to be able to bolt everything together and use the York compressor (that everyone seems to hate like an Edsel) so I can have working AC now (and check its efficiency first,  and possibly upgrade to a rotary compressor later?)  You can do this, IF you currently have a complete AC system in your car, and can reseal your compressor, or find a rebuilt one.

 

Do I want to fabricate a compressor bracket for a rotary compressor like Sanden (aftermarket,) Hitachi (Nissan used these in most their other lines of vehicles,) or upgrade to another brand (ie: Honda, etc.)   Then you could mate an old Evaporator (inside the car unit) with a modern compressor system. Vintage Air and other companies sell "ear" brackets that fit a Sanden compressor but they will still have to be welded to a plate to make a compressor mount. AND, it will have to be fitted to your block and aligned with a drive pulley.

Some of these companies sell a flat plate already welded to these ears that is intended to bolt to a block or some other bracket. But it too will still have to be fitted to your engine block and aligned with the drive pulley. As of today, I have yet to find a modern company still in business who makes a bolt-on compressor bracket and idler pulley/ bracket that is a ready bolt-on installation for a 620. (If you find one please msg me!) You will have to weld one up yourself, or have someone make it for you, then address the drive belt and hose-end connectivity. That is the hard / expensive part, especially if you don't have those skills and/or equipment.

 

I have seen posts suggesting using an original 720  mount bracket and compressor from 1981 and later 720 motors. That is NOT possible AND if it were... you would have to use a rotary Hitachi compressor. First: The bracket is cast iron and weighs about 10 lbs, and you can't weld on it unless you have some serious technical welding skills and materials. Second: The mounting tabs are also specific to a Hitachi compressor only. The mounting tabs are completely different from a York and a Sanden, these will not fit without serious adaptation, and would look horrible if so. Third: The bolt pattern to the L20B block is different from the 1981 and later engine block bolt pattern. 

 

 

If you have an existing Hitachi compressor and need a replacement, there is an outside chance Hitachi compressor maaaaaay still be available by aftermarket rebuilders on Ebay. But they will be extremely scarce if so. A super high-end technical AC shop may still be able to rebuild one. But, who is around who is that old and still has the specific knowledge about 40 year old compressors... that won't charge a fortune for it?   I couldn't find one for the longest time in So Cal and had one hell of a time locating one for my stock 1980 200SX, and that was 2 years ago. I still haven't installed it and don't know if it is a reliable rebuild or not. Keep your fingers crossed for me!

 

If you want to install any other compressor type like a Honda or some other brand, you'll have to conquer the same compressor mounting issues and hose-end fabrication  listed above.

 

Or you can buy a complete aftermarket modern "AC KIT" with and an under-dash evaporator unit, hoses, fittings, and a modern rotary compressor mount plate from a company like Vintage Air. BUT...you still have to conquer the compressor mounting issue. The last time I checked... Vintage Air and the other online companies DO NOT HAVE a ready-made bolt-on compressor mount solution.  If they do now, please PM me!  I would love to see it and buy one!

 

 

 

Edited July 30, 2018 by Seeker > 620 KC
Add Photo of 720 orig AC comp brkt, correct wording

[Seeker > 620 KC]

Here is a bolt-on AC compressor answer for all you sweaty 620 owners!

 

If you want to install a modern rotary Sanden compressor system in your Datsun 620 L20B AC system...

Good news! They are still being made today, available from various AC supply sources and in various configurations.

The hard part is finding a bolt-on bracket to mount it to your engine.

 

I networked around with my old automotive AC suppliers. One found this schematic in his treasured old AC parts catalog upstairs after all these years in their modern AC shop attic.   This is an ARA Air Conditioning aftermarket engine compartment schematic from the 70's showing everything their engine kit came with. It was made in the good ol' U.S.A. with plate steel compressor brackets, and barbed hose fittings and hose clamps to seal the hoses to the fittings. These hose ends typically leaked and were problematic, and made a tidy profit for the dealer's AC installation/ repair shop! lmao

 

 

 

The evaporator (inside the vehicle AC unit) was a separate "knee-knocker" unit that hung under the dash. It has "Datsun" in raised sliver lettering on the "On/Off switch plate similar to the gauge bezel trim...giving it the impression it was made my Nissan. It was not made by Datsun / Nissan. This is a typical after-market AC unit. There were a number of manufacturers who made these. One even put the rotary compressor on the passenger side, but they were not in business long and is very rare. Have yet to fine one myself for a template to reproduce. All the aftermarket automotive AC manufacturers including ARA are out of business &/or no longer produce these units.

 

In junk yards I've taken a number of these units apart that were already broken to prove this. If you pull the switches out of the plastic knee-knocker housing you'll find they say "Made in USA." If you look at the squirrel cage fan units you'll see they say "Made in Ohio.

 

I've heard 620 owners with AC brag their ARA or other after-market AC is "factory air." It is not. Factor 620 air was made by Nissan utilizing a York compressor and cast iron brackets, and the inside unit was inside the dash, not hanging below it.

 

I've heard 620 owners with AC in their truck brag  it was a "dealer option" which is an obscure and meaningless term today regarding Datsuns. "Back in the day" when I was a Datsun dealer employee... a true dealer option meant you could order a 5 speed trans in a car that typically came with a 4 speed. Or you could order something shipped from the Nissan factory  that was original Datsun/Nissan equipped and have it installed on your vehicle state-side (in the USA). This typically never happened with 620 Datsuns and earlier Datsun models. Why? Because Datsuns were brand new competing in the US market in the late 60's and 70's,  production was low. Datsuns only became seriously in demand by the public masses when the first fuel shortage happened.  There were very few Datsuns being delivered to a dealer monthly in the 70's, and the dealers had to take what they could get. Datsun Dealers would do almost anything to sell cars as they were.

 

Come talk to retired Datsun dealer George Goespel (sp?) at the next SWDP BBQ on Aug 18 in Fontana CA  and ask him questions about being a Datsun Dealer. He's great to talk to. If I recall correctly from my last conversation at a BBQ he said they only received 20-30 new vehicles a month. If they didn't have the specific vehicle a customer wanted, they had to trade with other dealers to get the one car they needed to make a sale. He said he often had to trade a couple vehicles for another coupled vehicles to get the one he needed. Then he'd be stuck with an "ugly" unpopular colored vehicle his salesmen couldn't sell. He contracted with a local auto/body shop to repaint the cars buyers wanted in specific colors and the ugly brand new cars and trucks so his people could sell them!

 

Back to "dealer options..."  Datsun dealers in different cities would buy the slotted mag wheels made popular in those days by Indy car racing, and later the "Jackman" style white spoked rims from local speed shops. They would install them on a new car /truck and put them in their show rooms to help sell the new Datsun models. (I still see Jackman style rims for sale on CL and the seller is selling them as 'factory rims!" lol)  Dealers would drill into brand new Datsun doors to install cheap aluminum side-molding, hang all kinds of mirrors from local parts stores, install oversized tires and rims,  hang local aftermarket step-bumpers,  and cut into brand new Dats roofs  to install aluminum/plexigalss moon-roofs... and call them "dealer options." How do I know this? I was one of those guys paid to install them. Early Datsun 620 Dealer options were typically local parts house aftermarket parts (typically crappy,) not parts made in Japan, and NOT supplied from Datsun/Nissan. In later 80's years when new models came out and the various Datsun production lines ramped up the later Z's had lots of actual Nissan options one could order from the factory, or buy from dealers. But never for 620's.   

 

Edited August 1, 2018 by Seeker > 620 KC

[knoriega]

Thank you for the kudos my dear friend.  Everything in your article is correct except for a few small details. As long as you use all factory installed a/c component for 1979 620, you only have to purchase a York to Sanden adapter to mount directly in place of the York compressor original mount location. You can re drill holes on adapter plate to line up Sanden compressor with pulley with original pulley tensioner that covers the timing belt cover. As long as you have complete system intact, all someone has to do is update York compressor to a Sanden compressor.  I completely dissembled my entire system and flushed with a/c flush (remove expansion valve

prior) (Spray system available from Autozone free loaner tool program). Replaced the expansion valve and receiver drier with new units which are dirt cheap. I used original flare fittings a/c hoses because I felt condition of hoses were decent. Before assembling everything back together, I lubricated all flare joints with a product called (Refrigeration Technologies RT201B Nylog Gasket/Thread Sealant) this helps seal all joints to keep refrigerant in system. I then used a vacuum pump to remove the air and moisture from the refrigerant system (vacuum pump available for free from Autozone free loaner tool program). All sanden pumps are r12 or r134 compatable, just depends which type of oil you use. I used AC Delco 15-117 air conditioning system mineral oil because I wanted to keep r12 system. System recommends 8 oz. mineral oil capacity for Datsun factory installed system. I then filled system to recommended r12 capacity of 2# of r12. My system had the 8 blade fan, my mistake is I did not replace the water pump with a new clutch. As you stated it is crucial. As far as being ugly, I disagree, the ugliness probably from my clustered engine bay..LOL.  It is all original placement from factory with only addition of upgraded Sanden compressor mounted in original pasenger side location. The bracket is supported with the two mount bolts that pivots the compressor adapter plate in towards the engine keeping it tight from movement as the tensioner pulley tighten the belt. As for coldness of air coming from vents, my system blows average 29 degrees at the vents. Seeker,  when you felt it I had just started my truck before leaving Eagle Rock (Reason why I chose to stay with R12). I must also give you kudos on a well informed wealth of info on a/c. As far as I am concerned, I like the the system,  it is old but works for our trucks.

 

Seeker great info

 

Parts used ordered on Amazon:

Four seasons expansion valve part # 38608

Refrigeration Technologies RT201B Nylog Gasket/Thread Sealant

Johnsen's 6545-6 A/C Flush- 32 oz.

York to Sanden adaptor mount purchased on Ebay https://www.ebay.com/itm/YORK-TECUMSEH-TO-SANDEN-COMPRESSOR-BRACKET-KIT-SD709-SD5H14-SD7H15/282598743519?epid=1717932436&hash=item41cc329ddf:g:Rr8AAOSwJS5ZhMyo:rk:4:pf:0

 

If I can assist anyone in the Los Angeles area, PM me.

 

 

 

[Charlie69]

The last year 510 with the L20B had an AC compressor mounted on the left side of the block under the smog pump like the 1980 720 L20B.  I do not remember what was the last year for the L20B in the 510.

[Seeker > 620 KC]

1 hour ago, Charlie69 said:

The last year 510 with the L20B had an AC compressor mounted on the left side of the block under the smog pump like the 1980 720 L20B.  I do not remember what was the last year for the L20B in the 510.

 

Good installation brainstorming idea Charlie! 

 

The important things you’ll want to check first  if you’re thinking of installing an original Datsun made  510 AC compressor in a 620 (especially if you still need to run a smog pump) are:

 

Is it an original cast Datsun made cast iron compressor bracket? 

If so, is it for a square York compressor, or is it for a rotary Hitachi compressor? 

Either way, for a bolt-in installation you’ll have to find an original rebuilt or resealed York or Hitachi compressor. 

This is because the Hitachi rotary compressor mounting tabs are different than for the after-markets Sanden compressor. 

 

Or you’ll have to locate/ fabricate an adapter bracket to use a Sanden after-market compressor like knoriega did. 

 

And, before buying a lot of parts you’ll need to ensure there is clearance between the compressor and the steering gear box. The steering box clearance is different between a 620 and a 720. 
 

If the 510 AC compressor bracket  is made from plate /bracket steel it is from a US made after market ac unit, probably an ARA unit similar to the 620 diagram posted earlier. (I have that installation diagram too.) It too can still be used, but you will still have to check clearance on the steering box first. 

 

 

[Charlie69]

The Brackets I am talking about are for the Hitachi compressor.  These are more HP friendly than the York compressors.

 

The VWs used the York compressors in the buses.

[Seeker > 620 KC]

9 hours ago, knoriega said:

Thank you for the kudos my dear friend.  Everything in your article is correct except for a few small details.

 

My system had the 8 blade fan, my mistake is I did not replace the water pump with a new clutch. As you stated it is crucial.

The day I saw your truck at ER Swap Meet it did not have an 8 blade fan installed, the fan clutch was shot and spun freely when off, &  your truck was running very hot close to over heating, and that is why you called me away from my selling space to give you guidance on it. I advised you install the correct Water pump / fan clutch, to install the correct 8 blade fan, and not to eliminate the  shroud. You tried to buy my new AC HD Delco WP/ fan clutch  for less $ than I was asking,  and I wouldn’t take your offer. But I did sell you the correct 8 blade fan. 

 

As far as being ugly, I disagree, the ugliness probably from my clustered engine bay..LOL.  Sorry, I did not mean to call your conversion work ugly. What  I meant to convey is...the original Datsun ac engine bay installation has far more brackets and looks clunky/complicated, vs a simple sanden compressor bracket in a 620 installation. i’m Very impressed you got it all in there and functioning well now, and in such tight spaces. You’re the first person i’ve shared my Sanden installation ideas with who actually installed them and got them working. 

 

As for coldness of air coming from vents, my system blows average 29 degrees at the vents. Seeker,  when you felt it I had just started my truck before leaving Eagle Rock (Reason why I chose to stay with R12). I suspect your thermometer is off, or needs calibrated. We tested these units new at the dealer after installation  and never blew that cold coming out of the vents.  (Isn’t 29 degrees well below feeezing point of 32 degrees?  These old  evaporators would freeze up ? )

 

I must also give you kudos on a well informed wealth of info on a/c. Thank you.

 

 

 

 

[Seeker > 620 KC]

8 hours ago, Charlie69 said:

The Brackets I am talking about are for the Hitachi compressor.  These are more HP friendly than the York compressors.

 

The VWs used the York compressors in the buses.

 

Right on Charlie. I have not looked into these and have not compared installed clearances to the frame and gear box.

Had a very difficult time finding one for my SX.

Have you found a source for rebuilt/re-resealed Hitachi compressors?